1. Field of the Invention
The present invention relates to a banding packing machine, and more particularly to an automatic banding packing machine comprising a band guide arch and serving to automatically detect that a band is not left in a band reel and the band in the band reel is used up in a series of operations for feeding the band toward the band guide arch side and pulling back the band from the band guide arch.
2. Description of the Related Art
For example, some automatic banding packing machines accommodate, in a packing machine body, a band reel around which the band is wound in a large amount (Japanese Patent Application No. 2002-67089).
In such a banding packing machine, the band reel is not protruded from the side surface of the packing machine body. Therefore, there is an advantage that a whole shape is small-sized.
On the other hand, in the conventional banding packing machine, a great deal of force is required for directly pulling a band out of the band reel and feeding the band toward the band guide arch side. Therefore, a primary storage chamber for a band having a small capacity which is referred to as a pool box or a back pool box is provided in the packing machine body.
The amount of the band required for banding at several times is prestored in the pool box. In the case in which the pool box is to be provided, moreover, a pool feed motor is disposed between the band reel and the pool box. The band is fed from the band reel into the pool box by the driving force of the rotating shaft of the pool feed motor.
On the other hand, in the case in which the back pool box is to be provided, only the excess of the band pulled back by one-time banding is stored in the back pool box. More specifically, the amount of the band required for banding at several times is not stored in the back pool box differently from the pool box.
In the banding packing machine provided with the primary storage chamber for the band which is referred to as the pool box or the back pool box, thus, the excess of the band left in the pool box or the back pool box is used for next banding.
In some cases in which the banding is to be newly carried out in the banding packing machine, however, the excess of the band stored in the pool box, particularly, in the back pool box causes a length to be insufficient. Accordingly, an amount of band further required should be directly pulled out from the band reel so as to be used.
In such a banding packing machine, the band prestored in the pool box or the back pool box is fed toward the band guide arch side with a small torque at a high speed, and the further required amount of band is pulled out from the band reel with a great torque at a low speed.
In such a conventional banding packing machine, it is detected in the following manner that the band reel accommodated in the banding packing machine body becomes empty and is to be replaced.
More specifically, for example, a photoelectric switch or a proximity switch is provided in a band running path on the way from the band reel to the back pool box, and the presence of the band is detected by means of the switch. When the signal is detected, it is decided that the band is used up and the subsequent operations of the banding packing machine are stopped. Thus, the final end of the band can be prevented from being fed into the band guide arch.
In order to detect that the band reel thus becomes empty, that is, the band is used up, however, the photoelectric switch or the proximity switch is conventionally required. Correspondingly, there is a problem in that a cost is increased.